First of all: there are obvs spoilers up in this piece. I actually had this movie semi-spoiled for me by someone on my Facebook feed the weekend it opened (bad form, by the by), so I read the Wikipedia article to see what the ending was, not really intending to see the movie. It's the kind of film that, if one of my friends wanted to go see it in the cinema, I would go, and gladly, but I wouldn't go of my own volition. Then my roommate brought a bootleg copy home, so I watched it. And you know what? I really liked it, even knowing (most) of the ending.
Also: best use of a one-note musical phrase since Terminator. So scary!
[it is EXTREMELY FOGGY]
Leonardo DiCaprio: So we gotta investigate this island for the criminally insane. I'm not sure why they're sending me here with a brand-new partner, but I'm sure we'll work well together. Also, my wife died, FYI.
Mark Ruffalo: Right, boss. I am as ruggedly handsome as the cliffs of this scary island are simply rugged.
[they ARRIVE and it is SUPER CREEPY]
Drew Carey's Brother: Surrender your firearms, and all your hope.
DCB: Um...nothing. Also, the only way to get on or off the island is at this one dock. Just so everyone knows.
[there is SCARY MUSIC]
Ben Kingsley: Welcome to my island. A woman named Rachel Solando has escaped, but as you can see, the rocky terrain would make it very difficult for her to leave the island. She drowned her kids and is living in a fantasy world. Phew, I think that's all the exposition we need, maybe.
Leo: Where's her main psychiatrist?
Ben Kingsley: He, uh, went on vacation.
Michelle Williams: I am your dead wife in a dream and I am telling you that this woman is still on the island and so is this other guy who supposedly doesn't exist wooooo I am deaaaaad!!
Leo: Hmm. My dead dream-wife sounds really sensible. I'm sure this mystery man, Andrew Laeddis, is here.
[they CLIMB AROUND on the island looking for her]
Leo: TELL ME WHAT YOU KNOW!!
Group Therapy Members: GET AWAY FROM HERE!!
Leo: Something weird is going on here.
Mark Ruffalo: Sure, boss.
Ben Kingsley: Oh, wait, we found the supposedly-escaped woman.
Emily Mortimer: What are you doing in my house? I am crazy.
Leo: Something VERY WEIRD is going on here.
[he BREAKS IN to a SECRET WARD]
That Pedophile-Lookin' Dude: You beat me up! Look at my face! You did this!
Leo: What? Huh? What? I just need to find Andrew Laeddis!
[some SCARY MUSIC plays]
Mark Ruffalo: Oh, look, I found the intake form for Andrew Laeddis. You can just read it and see what it says and then this mystery will be solved.
Leo: Um...maybe later.
Mark Ruffalo: Dude. This is, like, a key piece of evidence. Look at it!
Leo: LATER!! I need to concentrate on formulating my Nazi conspiracy theory!!
[they SCALE some CLIFFS and Mark Ruffalo FALLS, maybe]
Leo: Noooooooooooooooo! My newly-appointed partner who I feel so close to that I must scale these cliffs to saaaaaaaaaaaave!!!
[he goes in a CAVE]
Patricia Clarkson: Sup. I'm in a cave, and I have awesome dark hair, and I'm super hot, though I am 50. I am the real Rachel Solando, and I was a psychiatrist here, and I confirm all of your Nazi conspiracy suspicions!!
Leo: I was right about the Nazi conspiracies! I must save my partner! He must be in the lighthouse where they do the Nazi experiments!
[he SWIMS to the lighthouse and it is THRILLING]
Ben Kingsley: So, hey, listen. You know how you think you're a U.S. Marshal and you were investigating an escape and you were trying to find Andrew Laeddis? Turns out you're Andrew Laeddis and you have been here for two years because your wife drowned your kids and then you killed her.
Leo: Wait, whaaaaaaaa?
Mark Ruffalo: Hey, boss. I'm actually your psychiatrist, not your partner.
Ben Kingsley: We wanted to let you play out your fantasy so we could cure you, otherwise the board is gonna make us lobotomize you. So are you cured?
Mark Ruffalo: What's our next move, boss?
Leo: Well, it looks like this conspiracy goes deeper than I thought! Would you rather live as a monster or die as a good man?*
[presumably, they SNIP his BRAIN and he is a ZOMBIE]